Effect of geometric nonlinearity on the ultimate lateral resistance of piles in clay

In this note we investigate how the assumption of small deformations affects the estimation of the ultimate resistance to lateral pile movements in clay. For that we perform coupled hydro-mechanical finite element analyses, using the Modified Cam Clay model to describe soil behaviour. Validation of the numerical methodology via small-strain analyses is followed by an investigation on how the ultimate resistance diverges from exact plasticity solutions when large displacements are considered. Results suggest that the failure mechanism depends on the pile displacement required to mobilise the ultimate resistance, and that small-strain plasticity solutions provide upper bounds of the ultimate resistance.